Apple has continued to send out invitations to users of its iCloud backup and sync service to try the beta of iWork for iCloud, the online word processing, spreadsheet and presentation-making apps slated to release to everyone later in the year.

The suite -- Web-based versions of Pages, Numbers and Keynote -- debuted in June at Apple's Worldwide Developers Conference, where a company executive briefly demonstrated the new tools.

Although Apple said nothing about how much, if anything, iWork on iCloud will cost, the executive promised a public beta would launch "later this fall."

Registered developers immediately received access to the under-construction apps.

Since June, Apple has slowly been extending beta invitations to the public. In the last two weeks Computerworld has received ongoing reports of invitations reaching iCloud users' inboxes.

"We'd like to invite you to be one of the first to try it, so we're giving you early access to the iWork for iCloud beta," the emails stated. "All you have to do is sign in to iCloud on a Mac or a PC using the current version of Safari, Chrome, or Internet Explorer."

As the emails noted, the beta supports just three browsers: Apple's own Safari, Google's Chrome and Microsoft's Internet Explorer (IE). Apple has promised to expand the list, presumably to Mozilla's Firefox and Opera Software's Opera, both of which run on Windows and OS X.

Other features on Apple's to-do list include printing, version history and pairing a link with an iWork document stored in iCloud for sharing with others.

Most analysts believe Apple will give away iWork to iCloud to iPhone, iPad and Mac owners, as it does currently for iCloud itself, as another way to entice customers into buying the Cupertino, Calif. company's hardware. The competition -- Google Docs and Microsoft's Office Web Apps -- is also free.

Other pundits, including Ryan Faas, who frequently writes for Computerworld, have speculated that Apple may see iWork for iCloud as an extension of iWork on iOS and OS X.

iWork on those platforms is sold as individual apps, priced at $9.99 for iPhones and iPads, and $19.99 each for Macs. Apple will upgrade iWork this fall, the first time that the OS X version has been refreshed since 2009.

If Faas is correct -- and others have voiced the same opinion -- then iWork for iCloud may be available only to those who have purchased the iOS or OS X software. In that scenario, Apple would essentially be using the same model as Microsoft, whose Office on the iPhone and Android smartphones runs only if customers also have an Office 365 "rent-not-buy" software subscription.

Apple continues to send invitations to the beta of iWork for iCloud to customers as it expands the program beyond developers. (Image: Apple.)